有一种方法可以获得阵列的所有键？

Question

我希望得到数组的所有键,将每个键与数字进行比较,这样的事情:

array(
[0] => 7
[1] => 8
[2] => 4
[3] => 6
)

if (6 != EACH KEY OF ARRAY) {
    so...
}

条件不会显示,因为有[3] => 6,当然键6 = 6.

有功能吗？别的什么？

Answer 1

.

foreach($array as $key => $val)
{
  if (6 != $key) {
   // so...
  }
}

例:

$array = array(7, 8, 4, 6);

foreach($array as $key => $val)
{
  if (6 != $key) {
   echo '6 is not equal to ' . $key . '<br />';
  }
  else {
   echo '6 is equal to ' . $key . '<br />';
  }
}

结果:

6 is not equal to 7
6 is not equal to 8
6 is not equal to 4
6 is equal to 6

但是,如果要检查数组中是否存在6 的值,请使用in_array如下所示:

if (in_array(6, $array)) {
  // 6 is present in the array
}